Media for use in making camera copy and method of preparing same



July 1, 1945. M. D. MCINTOSH MEDIA FOR USE IN MAKING CAMERA COPY AND METHODS OF PREPARING SAME 2 Sheets-Sheet 1 Filed July 30, 1942 INVENTOR. MAURICE D- M INTOSH.

ATTORNEYS.

.Jufiy w, E9451. M. D. MCINTOSH 2,379,915

MEDIA FOR USE IN MAKING CAMERA COPY AND METHODS OF PREPARING SAME Filed July so, 1942 2 Shets-Sheet 2 INVENTOR. MAURICE D. M INTOSH 1mm, ZMWMM ATTORNEYS.

Patented JulylO, 1945 MEDIA FOR USE IN MAKING CAMERA COPY AND METHOD OF PREPARING SAME Maurice D. McIntosh, Cleveland Heights, Ohio, gslililignor to Louis S. Sanders, Shaker Heights,

Application July so, 1942, Serial No. 45am 10 Claims. (Cl. 41-41) This invention relates, as indicated, to media for use in making camera copy, and to methods of preparing the same.

In my Reissue Patent No. 20,503, I have described a drawing paper having a plurality of normally invisible patterns, one of the patterns being developable by a developer solution capable of developing said pattern only and both of the patterns being developable by a developer solution capable of developing both of the patterns collectively.' In the specific example described ln said patent, one of the patterns consists of a plurality of geometrically arranged dots located in equally-spaced diagonal rows in such a manner that the dots in one of the rows align with adjacent dots in the other rows to form diagonal rows extending transversely of the firstnamed rows. The other pattern consists of diagonal lines extending longitudinally of and in registry with the respective diagonal rows of dots.

While this method of forming the patterns is, in general, satisfactory, its value depends to a great extent on securing perfect registry or propor relative location between the dots and lines, a condition which is often exceedingly dimcult to obtain by the ordinary method of forming the patterns, that is, printing the patterns by means of plates.

I have discovered however, that I can secure perfect registry or proper relative location between two different patterns by the simple expedient of printing on a suitable sheet or surface two so of closely spaced parallel lines of chemically developable material, one set of lines crossing or intersecting the other set of lines at an angle of 90 degrees. In this way, I have been able to provide a medium which is not onlyusefull for general drawing purposes, but which is especially adapted for use in the preparation of camera copy for multicolor printing.

The invention can probably best be understood by reference to the accompanying drawings, wherein Fig. l is a plan, view of a fragment or corner portion .of a base sheet, illustrating the first imprint thereon;

Fig. 2 is a view similar to Fig. 1, but showing the second imprint as :well as the'flrst;

Fig. 3 is a view similar to Fig. 2, but showing the sheet after removal 01 the soluble portions of the lines forming the second imprint;

Fig. 4 is a view of the sheet as shown in Fig. 3, alter development of the mercurous chloride pattern;

Fig. 5 is a view of the sheet as shown in Fig. 3, after development of boththe mercurous chloride and basic lead sulphate patterns;

Fig. 6 is a view similar to Fig. 1, but illustrating the first imprint in the preparation oi. a modified form 01' the medium of the invention;

Fig. '7 is a view similar to Fig. 6, but illustrating the second imprint, as well as the first;

Fig. 8 is a view of the sheet removal of the varnish lines;

Fig. 9 is a view of the sheet, after development of the mercurous chloride pattern, and

Fig. 10 is a view of the sheet, after development of the mercurous chloride and lead sulphate squares.

Referring more particularly to Figs. 1 to 5 of the drawings, I first take a sheet of paper, cellulose acetate or nitrate film, ethyl cellulose fllm or similar material, which I have designated by reference numeral 2 in Fig. 1 of the drawings, and the surface of which is smooth, relatively impermeable to water and oifers poor adhesion to glue. Sheets of cellulose acetate, cellulose nitrate and ethyl cellulose, in the condition in which they are usually available in the market, are satisfactory. Where, however, it is desired to use paper as a base, it is necessary to adhesively secure one oi the foregoing cellulose sheets to the paper so as to provide a suitable surface, or to coat such paper with any one of a number of available we.- terproof lacquers, varnishes or synthetic resins.

For the purpose of the present description, it will be assumed that paper coated with a thin sheet 2 of cellulose acetate is used as the base of the drawing medium.

Using an ordinary printing plate bearing aparallel line pattern, in which thelines are as wide as the spaces between them, the first imprint consisting of such lines, designated 3, is printed. This imprint is made with ordinary white printing ink or clear printing varnish, applied directly to the acetate. Before the ink or varnish is dry and while it is still tacky, it is dusted with basic lead sulphate, a fine white powder. Various mechanical methods may be employed to dust the ink or varnish pattern, but it is notonly necessary to bring the powder in con tact with the tacky ink or varnish to have it adhere sufficiently to cover the whole ink or varnish surface. The dusted ink or varnish is then permitted to dry and firmly hold the powder embedded in its upper surface.

The entire surface of the sheet is then sponged gently under a spray oi! water to remove all excess and unbound or unembedded powder. The sheet is then dried by running it through soft rubber rollers, blotting, or other means, and is then ready to receive the second imprint.

The second imprint, consisting of the lines 4 shown in Fig. 2. is made with a printing plate identical with that used for making the first imprint, but the lines of which extend transversely lowing composition, and treated in the following manner: e

. Parts Liquid glue (Le Page's) 120 Glycerol 60 Light blue watercolor solution (Eastman's- Velox) 35 Water (distilled) 300.-

Mercurous chloride (precipitated powder) 900 After this ink has been ground on a stone paint mill several times or until the mercurous chloride powder is completely and very finely dispersed, 230 parts of diethylene glycol are added.

This ink is normally soluble in water, even when dry. but when imprinted as lines across the first imprint of dusted varnish lines, it penetrates the dusted lines at the points of superimposition and becomes insoluble, while the portions of the lines of soluble ink that fall on the cellulose acetate surface between the varnish lines remain Parts -Water 100 Thiourea 1.7

The developer does not afiect the portions of the lines 3 between the dots, so that the developed pattern appears as a relatively light tone, useful for light tone effec in the drawing which will ultimately be used f camera copy.

The line pattern which contains both mercurous chloride and basic lead sulphate may then be developed to visibility, as shown in Fig, 5, by means of a chemical developer composed of the following:

- Parts Water 100 Sodium sulphide 5 This developer efleets both the dots and the portions of the lines t between the dots, so that the developed pattern appears as a relatively dark tone useful for dark tone effects in the drawing which will ultimately be used for camera copy.

The sheet,after the final washing referred to above, is uitable for use, but the surface is not one that will readily accept the chemical developers to which reference has been made or india drawing ink, with which the line drawings are usually made. It can be improved in this respect by the application of a suitable surface coating. Such a'coating can be prepared as follows:

Parts Water 1000 Corn star 60 Gelatin (dry) 50 Soak one half hourand with stirring melt to, 120 F. I

Add slowly with stirring 700 parts isopropyl alcohol.

Just prior to coating add 5 parts formalin.

Keep solution at 80 F. while coating and apply ofor at 90 degrees to those of the first plate. This on a regular engravers plate coating machine for second imprint is made with an ml: of the 101- good uniformity of coating thickness.

For some purposes, particularly that described in the'copending application of Louis S. Sanders, Serial No. 451,700, it is desirable to have a medium of the character described, on a transparent base, rather than on paper. For such purposes, it is only necessary to print the patterns on heavy weight sheet material of cellulose acetate, cellulose nitrate, or ethyl cellulose. Material of a thickness ranging from .003" to .010" is suitable. With such a material as a base the preparation 7 of the drawing medium is essentially the same as that described above in connection with the preparation of the paper base medium.

It will be apparent from the foregoing that by forming patterns of intersecting lines, perfect registry orproper relative location between the patterns is readily obtained, without the necessity of taking any, undue precautions during the imprinting of the patterns.

It will also be apparent that in cases where a transparent base is employed, the medium is especially useful in multi-color work, since the light pattern or tone is available to indicate a light shade of a selected color, and the dark pattern or tone is available to indicate a darker shade of said color.

As a modification of the invention, instead of using waterproof coated or laminated paper as the base of the medium, a gelatin coated paper sheet may be used, such for example, as imbibition paper furnished by Eastman Kodak Company. This is a hard smooth coated paper bearing a surface of plain hardened gelatin.

Using the same line printing plate as already described, there is imprinted upon this gelatinsurfaced paper a first pattern with a waterproof printing varnish or ink. This varnish imprint, consisting of the lines iii in Fig. 6, is permitted to dry and then crossed, as in the previously described method, with a line print .of mercurous chloride ink. In this instance, the mercurous chloride ink adheres permanently to the gelatin surface betweenthe varnish lines as well as to the lines themselves, and is shown as the lines H in Fig. 7.

After the mercurous chloride ink has been permitted to dry the sheet is immersed for about 30 seconds in a solution containing 7 Parts Water 100 Lead acetate (normal) 5 The excess of this solution is removed by rollers or blotting, and the sheet is then immersed for five or ten seconds in a solution containing Parts Water 100 Sodium sulphate (anhydrous) 8 able, since it has low flammability and is nononly the ink which adhered to the gelatin surface between the lines it. This remaining mercurous chloride ink is-in the form of isolated squares and constitutes the dot pattern. The lead sulphate also remains as squares alternating with the mercurous chloride squares. Together, these form continuous lines, as shown in Fig. 8, and by Joint development, form the line pattern.

The mercurous chloride squares may be developed. as indicated in Fig. 9, by means of the thiourea solution which has been previously described. The mercurous chloride and lead sulphate squares may be collectively or simultaneously developed.

as indicated in Fig. 10, by means of the sodium sulphide solution which has previously been described.

In this modified method of forming the medium, other chemicals may be substituted for the lead sulphate, such as cobaltous phosphate, nickelous phosphate, cupric tungstate, ferric phosphate, thallium tungstate or other insoluble metal salts which will produce non-actinic colored precipitates with a soluble sulphide, such as the sodium sulphide solution to which reference has been made.

With further reference to the modified method 5. In a method of preparing a, medium for use in making cameracopy, the steps which consist in imprinting upon a gelatin-coated surface a series of parallel lines of a varnish, then imprint ing said surface with spaced parallel lines extending angularly to said first-named lines, and containing mercurous chloride, then immersing said surface in chemicals whose reaction produces an insoluble precipitate of lead sulphate in the spaces enclosed by said lines, and then removing said varnish lines by means of a suitable solvent.

6. In a method of preparing a medium for use in making camera copy, the steps which consist in imprinting upon a gelatin-coated surface a se 7 ries of parallel lines of a waterproof varnish, then imprinting said surface with spaced parallel lines extending angularly to said first-named lines, and containing mercurous chloride, then of forming the medium, it will be understood that while the method has been described in connection with gelatin-coated paper, that a transparent medium can be formed in the same manner,- by starting with a transparent base sheet, as deji scribed in connection with the first form -of the acoating of gelatin such a base sheet. In this way, the medium thus invention, and applying prepared is suitable for multicolor work.

Iclaim: 1. In a method of preparing a medium'forjuse in making camera copy.

of spaced parallel lines of a tacky substance, dusting said surface with basic lead sulphateto there by cause said sulphate to adhere to said lineare' moving said sulphate from the other portions of said surface, imprinting said surface with spaced parallel lines extending angularly to saidf-ilrst named lines and by means of an ink containing mercurous chloride, and then removing said ink from all portions of said surface except at the points where the ink is superimposed on said firstnamed lines.

2. A method, as deilned in claim 1, in which the surface. as a final step, is covered with a coating which improves the ability of the surface to accept chemical developers and drawing ink.

3. In a method of preparing a medium for use in making cameracopy. the steps which consist in imprinting upon a surface a series of spaced parallel lines of a waterproof substance. then imprinting said surface with spaced parallel lines extending angularly to said first-named lines, and containing a chemicaily-devslopable material,

the steps which cfiliblstf in imprinting upon a surface a pattern-consistingar we successively immersing said surface in solutions of lead acetate and lead sulphate, whereby to form an insoluble precipitate of lead sulphate in the spaces enclosed by said lines, the varnish lines serving as a resist to said solutions, and then dissolving and removing the varnish lines from said surface.

7. A medium for use in preparing camera copy, said medium consisting of a surface having chemically-developable patterns thereon, said patternsconsi'sting of spaced parallel continuous rowssof contiguous segmental pattern areas, al-

"sleg' ental pattern areas of said rows being nejgchemical to form a dot patd sai rowsj'ingtheir entirety being develso fan'otherchemical said rows lita aid gsurfacewhichare nonresponsive hemicaliy mtlier'of,said.;-chemicals,-

1 ediumf-fo 1 use fine'preparin'g camera --said;-medi1 1m.9chsisting .ofa surface having 'r'nlcallydevelopabl'eff:lpatterns thereon, said consisting of spacedflparallel continuous rows:

rnate segme'ntal areas in said rows containing sulphate and the remaining areas of said taining mercurous chloride whereby said lesson 1- areas may .be selectively chemically developed. tozprovidejvisible dot patterns of dif-h ere denslueajssm rows of segmental pattern "area Il sseparated by portions of said surface whi h-arezfnonresponsive chemically to developcrs ofeither of said chemicals.

and then applying a chemicaily-developable material, other than said first-named material, to

the spaces'enclosed by said lines.

4. In a method of preparing a medium for use in making camera copy, the steps which consist in imprinting upon a gelatin-coated surface a series of parallel lines of a waterproof substance, then imprinting said surface with spaced parallel lines extending angularly to said first-named lines, and containing mercurous chloride, then applying achemically-developable material, other than mercurous chloride, to the spaces enclosed by the lines, and then removing said first-named lines from said surface.

9. A medium for use in preparing camera copy.

said medium consisting of a gelatin-coated sheet,

the surface of which bears chemically-developable patterns, said patterns consisting of spaced parallel continuous lines, uniformly spaced sections of which contain a chemically-developable material. and the sections of which intermediate said spaced sections contain a chemically-developable material other than said first-named material.

10, In a method of printing camera copy'the pattern;}are'as' being separated byv 'con'tiguous "segmental pattern areas al 

